Five new embryos and new surrogate mothers added to the Northern White Rhino rescue project

Four years since this ambitious project began, scientists and conservationists working to save the northern white rhino using artificial reproduction methods as part of the BioRescue project have made significant progress towards their goal. The project has already produced 29 northern white rhino embryos, which are stored in the laboratory and ready to be transferred into surrogate mothers. Five new embryos were prepared during the last cycle of procedures.

During the last scientific field trip to Kenya in May 2023, the 13th egg collection from the Northern White Rhinoceros (NWR) was carried out by a team of scientists and conservationists from the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW), Ol Pejeta Conservancy, Safari Park Dvůr Králové, Kenya Wildlife Service (KWS) and Wildlife Research and Training Institute (WRTI) at Ol Pejeta Conservancy in Kenya. The procedure with the female Fatu went smoothly without any complications and 18 eggs were harvested. They were matured and fertilised at the Avantea lab in Cremona, Italy, leading to 5 further embryos being produced, the highest number of embryos from any one egg collection so far. Previous procedures in November 2022 (11th collection) and February 2023 (12th collection) yielded two and zero embryos, respectively.

Furthermore, in May 2023 the BioRescue team made another promising step towards saving the most endangered mammal species on our planet. The consortium members successfully identified and selected two wild southern white rhino females (SWR) as potential surrogate mothers. Both females were examined and translocated into a safe enclosure. They will now be crucial in supporting the breeding efforts within the BioRescue project for the NWRs.

The consortium members also checked the health status of the SWR teaser bull Ouwan and confirmed that he is still functionally sterilised. The teaser bull indicates by copulating with a female that a potential SWR surrogate mother is ready to receive an embryo. The bull has to be sterilised, otherwise it makes no sense to perform an embryo transfer as the female would become pregnant with the bull’s sperm.

The next steps of the BioRescue project will be to perform embryo transfers with SWR embryos to demonstrate that the chosen transfer protocol is suitable and works. Once a proven pregnancy is achieved the team will use the protocol for transferring cryopreserved NWR embryos to produce viable offspring as soon as possible.

All steps of the BioRescue project are monitored and accompanied by an ethical evaluation procedure developed and implemented by the Ethics Laboratory for Veterinary Medicine, Conservation and Animal Welfare at Padua University in Italy. Apart from BMBF, other major donors to the NWR BioRescue project include foundation Nadace ČEZ and Richard McLellan.